The headquarters of the Metropolitan Police has been sold for £370million to a multi-billion dollar alternative investment company based in Abu Dhabi.

The proceeds of the sale - which secured £120m more than the guide price and three times what was originally paid for the site freehold in 2008 - will be invested in technology for police officers such as tablets, smartphones and body cameras.

The New Scotland Yard site, situated next to St James's Park Tube station and famed for its revolving triangle sign which will remain there, will become residential, and will probably also feature offices and a hotel, according to London mayor Boris Johnson.

Asked if he feared there would be criticism that another investor from overseas has moved into the capital, Mr Johnson said there is no economic difference between "having an investor from Abu Dhabi or having the BP pension fund do this".

Marketed as Ten Broadway, the 1.7-acre site and 600,000 square foot building attracted intense interest from around the world.

There were 11 credible bids and Abu Dhabi Financial Group (ADFG) secured the deal.

Having financed other central London developments, including the 1 Palace Street project adjacent to Buckingham Palace, the group now proposes to create a mixed-use residential development on the site, the mayor's office said.

ADFG said it plans to create a "world-class development".

The operational HQ of the Met is now on the move to the Curtis Green building on Victoria Embankment.

Currently undergoing a £58 million transformation into a slimmed-down HQ, this relocation is predicted to save the Met more than £6 million a year in running costs.

Mr Johnson described the new HQ as a "pretty nondescript building...a lovely building obviously".

He said that while New Scotland Yard would be redeveloped, the "special triangle jobby" - the revolving sign outside - would be kept.

He added: "The Met Police has a unique place in history and they need a home fit for the future, but police budgets are under real pressure.

"The sale of this under-used and outdated building means we can now not only protect that rich heritage, but also fund the new HQ and kit out bobbies with the latest mobile technology to secure the future of the force.

"This landmark deal allows us to preserve the past whilst giving today's Met a vital cash boost so our officers can go on keeping London safe."

Jassim Alseddiqi, chief executive of ADFG, said: "Ten Broadway will be one of the most important redevelopment projects undertaken in Central London this decade, replacing a world famous headquarters with a world class development.

"With the bid process now complete, we look forward to creating an exceptional new landmark for London."